Process of treating fibrous materials with the reaction product of methylolphosphine adducts and nitrogenous compounds

ABSTRACT

Soluble methylol phosphine adducts which contain one or more methylol phosphine radicals (PCH2OH) are prepared by reacting in a suitable solvent tris(hydroxymethyl)phosphine with an amide or amine which contains one or more hydrogens attached to trivalent nitrogen. These soluble adducts are particularly valuable for the preparation of thermosetting flame resistant polymers by reacting them with nitrogenous compounds which contain two or more hydrogen and methylol groups attached to trivalent nitrogen. The adducts are also valuable for the preparation of flame-, glow-, wrinkle-, and shrink-resistant knit and woven textiles by causing the adducts to react with nitrogenous compounds in or on the textile structure by application of heat.

United States Patent [1 1 Reeves et al.

[451 Oct. 29, W74

[ PROCESS OF TREATING FIBROUS MATERIALS WITH THE REACTION PRODUCT OFMETHYLOLPI-IOSPI-IINE ADDUCTS AND NITROGENOUS COMPOUNDS [73] Assignee:The United States of America as represented by the Secretary ofAgriculture, Washington, DC

[22] Filed: Nov. 15, 1972 [21] Appl. NO.: 306,774

Related US. Application Data [62] Division of Ser. No. 141,362, May 7,1971,

abandoned.

[52] US. Cl 117/136, 117/138.8 UA, 117/141, ll7/143 A, 117/143 R [51]Int. Cl C09d 5/18 Field of Search... 117/136, 141, 143 A, 143 R,

ll7/l38.8 F, 138.8 N, 138.8 UA; 260/606.5P

[56] References Cited UNITED STATES PATENTS 3,619,113 11/1971Stockeletal. ll7/l36X 3,698,854 10/1972 Donaldson et a1 117/137 XPrimary ExaminerWilliam D. Martin Assistant ExaminerTheodore G. DavisAttorney, Agent, or Firm-M. I-loward Silverstein; Max D. Hensley [5 7]ABSTRACT Soluble methylol phosphine adducts which contain one or moremethylol phosphine radicals (PCI-I OH) are prepared by reacting in asuitable solvent tris( hydroxymethyl)phosphine with an amide or aminewhich contains one or more hydrogens attached to trivalent nitrogen.These soluble adducts are particularly valuable for the preparation ofthermosettingflame resistant polymers by reacting them with nitrogenouscompounds which contain two or more hydrogen and methylol groupsattached to trivalent nitrogen. The adducts are also valuable for thepreparation of flameglow-, wrinkle-, and shrink-resistant knit and woventextiles by causing the adducts to react with nitrogenous compounds inor on the textile structure by application of heat.

10 Claims, No Drawings PROCESS OF TREATING FIBROUS MATERIALS WITH THEREACTION FIiODUCT OF METHYLOL- PHOSPHKNE ADDUCTS AND NITROGENOUSCOMPOUNDS This is a division, of application Ser. No. 141,362, filed May7, 1971 now abandoned.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to new phosphorus and nitrogen containing solublecompounds, to thermosetting polymers which contain phosphorus andnitrogen, and to procedures employing the use of these compounds andpolymers for the production of flame-resistant fibrous organicmaterials. More specifically, this invention provides a process forpreparing soluble nitrogencontaining methylolphosphine adducts andmethods for their utilization in the production of thermosettingflame-resistant polymers and for the production of flame-resistantorganic textiles.

As employed throughout the specifications and claims of this invention,the term THP refers to the compound tris-(hydroxymethyl)phosphine, (HOCHP. The term methylolphosphine adduct refers to soluble compoundsproduced by reacting THP with certain nitrogenous compounds.

Co-pending application Ser. No. 265,861 by Daigle, Drake, Pepperman, andReeves filed June 23, 1972, and now abandoned relates to the productionof polymers through the reaction of tris(hydroxymethyl)phosphine withnitrogenous compounds containing at least two members of the grouphydrogen atoms and methylol radicals (CH OH) attached to trivalentnitrogen atoms either in the presence of free formaldehyde or not.

A primary object of the present invention is to pro videmethylolphosphine adducts which are stable toward further reactionduring storage but which'are capable of further reaction with certainnitrogenous agents to produce thermosetting flame resistant polymers andflame resistant organic textiles.

We have now discovered that tris(hydroxymethyl)- phosphine reacts withmonomeric nitrogenous compounds which contain at least'one member of thegroup hydrogen atoms and methylol radicals (-CH OH) attached totrivalent nitrogen atoms, either in the presence of free formaldehyde ornot, to produce soluble methylolphosphine adducts. We have alsodiscovered that these adducts can be further reacted with nitrogenouscompounds which contain at least two members of the group hydrogen atomsand methylol radicals attached to the trivalent nitrogen to producenitrogen and phosphorus containing. polymers or flameandwrinkle-resistant textile products.

More specifically, the products and processes of our invention may bedescribed as follows: (l) Soluble methylolphosphine adducts are preparedby reacting THP either in the presence of free formaldehyde or not withan essentially monomeric amide or amine in a suitable solvent. In orderto make the soluble and useful adducts of this invention there must bean excess of methylol phosphorus radicals (PCH OH) in the adduct. Forpurposes of the reaction THP is trifunctional; the

where m and n are integers of l or 2 and the sum of m n is 3. (2) Toproduce thermosetting polymers in accordance with this invention, themethylolphosphine adduct is reacted with a nitrogenous compoundcontaining at least two members of the group consisting of hydrogenatoms and methylol radicals attached to trivalent nitrogen atoms. Thereaction is carried out by dissolving the methylolphosphine adduct andthe nitrogenous compound in a suitable medium and then heating as neededuntil a viscous solution and finally a solid polymer is produced. Thepolymers produced by this process are insoluble, thermosetting, andflame resistant. The polymers contain reoccurring trimethylenephosphorus radicals which can be oxidized to a trimethylene phosphineoxide structure v OP CHrN (3) To produce flame resistant organictextiles the textile structure is wetted with a solution containing themethylolphosphine adduct and nitrogenous compound containing at leasttwo members of the group consisting of hydrogen atoms and methylolradicals attached to trivalent nitrogen atoms, then drying and heatingthe textile atan elevatedtemperature ranging from about to C. for aperiod of time necessary to promote copolymerization of themethylolphosphine adduct and the nitrogenous agent, within or on thetextile structure.

Nitrogenous compounds suitable for use in preparing themethylolphosphine adducts are virtually any essentially monomericnitrogenous compound which contains at least one member of the grouphydrogen radicals and methylol radicals attached to trivalent nitrogen.Suitable nitrogenous amides include cyanamide, formamide, urea,thiourea, melamine, acrylamide, octadecylamide, glycine and the methylolderivatives of these amides. Sulfonamides and phosphoramides are alsosuitable. Suitable amines include methylamine, dimethylamine,ethylamine, diethylamine, phenylamine, diphenylamine, phenylmethylamine,methylcetylamine, and aniline.

Methylolphosphine adducts of this invention are prepared by agitating asolution of THP and a nitrogenous compound until reaction occurs betweenat least one methylol phosphorus radical and one nitrogen atom on eachnitrogenous molecule to produce the structure The preferred solvent iswater, however, alcohols such as methanol, ethanol, isopropanol, anddimethyl formamide, dimethyl sulfoxide, and the like are very effectivemedia. The amount of solvent can be varied as desiredJThe adducts areused in solution, therefore, it is not necessary to isolate them assolids. Catalysts, other than heat, are generally not needed to promotethe reaction of THP with nitrogenous compounds to form soluble adducts.However, catalyst can be used when desired. Suitable catalysts includeprotonic acids. It is desirable to maintain the pH of the reactingsystem within certain limits. The preferred pH range is from 3 to 7. AtpHs substantially below 3, the reaction rate is greatly reduced. At pHssubstantially greater than 7, THP is oxidized totris(hydroxymethyl)phosphine oxide, which is not very reactive.

The soluble methylolphosphine adducts of this invention have someparticular advantages over the use of THP in the preparation of polymersand flame resistant organic fibrous materials. The adduct resistsoxidation to the phosphine oxide when heated.

Suitable nitrogenous compounds for use with the methylolphosphineadducts in the production of thermosetting polymers include virtuallyany soluble nitrogenous compound containing at least two members of thegroup consisting of hydrogen atoms and methylol radicals attached totrivalent nitrogen atoms. Examples of suitable amides include urea,thiourea, melamine, cyanamide, ethyleneurea, propyleneurea, dicyanamide,hydroxyethylcarbamate, octadecamide, acrylamide, amino acids, methyloland alkylated methylol derivatives of these amides. Examples of suitableamines include ethylamine, methylamine, ethylene diamine, aniline andcetylamine. Mixtures of these amides and amines can suitably be used.

Thermosetting polymers of methylolphosphine adducts with nitrogencompounds are principally prepared by agitating a mixture of the adductand the nitrogen compounds in a solvent system while heating untilcopolymerization occurs. The preferred relative amounts ofmethylolphosphine adduct and nitrogen compounds used to copolymerize canbe calculated by conventional methods for condensation polymerizationreactions assuming that functionality of the adduct equals the number ofmethylol phosphorus radicals on the adduct and the functionality of thenitrogenous agent is equal to the sum of the number of hydrogen andmethylol groups attached to trivalent nitrogen. Useful products maycontain only about one mole of the adduct per ten moles of nitrogenouscompound and as much as about three moles of the adduct per mole ofnitrogenous compound. The use of small quantities of the adduct withlarge quantities of nitrogenous compound is made practical when thenitrogenous compound contains N-methylol radicals which permit thecompounds to form condensation polymers even in the absence of theadduct. Polymers produced in accordance with this invention containreoccurring groups This group can be oxidized with oxidants such asperoxides, perborates, peracids and the like to the structure tures ofthese with noncellulosic fibers which can be impregnated with a liquidand dried and cured. Where textile structures are being treated inaccordance with this invention, the structure may be composed of amixture of various fibers. The polymers produced in or on fibroustextile structures are more effective in reducing the combustibility ofthese products which consist only of cellulosic fibers. Whennoncellulosic fibers are present, best results are obtained when thestructure contains 50 percent or more cellulosic fibers except when thenoncellulosic fiber is itself flame resistant. Examples of flameresistant organic fibers which can be blended with cellulosic fibers andtreated in accordance with this invention are those made ofpolyvinylchloride, polyacrylonitrile, and polyvinylidine chloride. Theseflame resistant fibers may be blended with the cellulosic fibers insubstantially any proportion and are successfully treated for reducedcombustibility by the process of this invention.

Where a textile is being impregnated, it is of advantage to removeexcess impregnating liquor by passing the textile through squeeze rollsprior to drying or curing the impregnated textile, It is alsoadvantageous to dry and heat the textile from about to C. for a periodof time necessary to promote copolymerization of the adduct and thenitrogenous agent. The preferred heating temperature is from about l30-l60 for one to 10 minutes.

The degree of flame resistance imparted to a textile by the products ofthis invention can be varied from a low degree to a very high degree byvarying the amount of polymer put in the textile. Textiles treated inaccordance with this invention are not only flame resistant, they arealso glow resistant, shrink resistant, mildew and rot resistant, andexhibit increased dimensional stability. The properties imparted totextiles by this process are durable to repeated laundering anddrycleanmg.

Surface active agents, water repellents, soil release agents, and othertextile treating agents may be incorporated into the solution treatingmedia to modify the treated textiles.

The following example is illustrative of the invention:

EXAMPLE 1 were heatedfrom about l20l 50 C. to produce flame resistantthermosetting polymers. These are described in Table lll. To produceflame resistant fibrous materials the structures were impregnated withcopolymer solutions then heated to produce insoluble polymers in or onthe fibrous structure as described in Table IV.

Table I SOLUBLE METHYLOLPHOSPHINE ADDUCTS Adduct No. Reactants ReactionConditions I 62 g. THP (0.5 mole) Mixed together at room tempera- 42 g.Cyanamide ture. After 1 hour extreme (50% soln.)(0.5 mole) exothermicreaction. Yellow 90 g. H moles) solution. Let stand at room temperaturefor 3 hours more. Cooled in ice box and let stand at room temperature.(42.8% solids) 2 62 g. THP (0.5 mole) Mixed together at room tempera- 21g. Cyanamide ture. Heated on steam cone for (50% soln.)(0.25 mole)minutes. Extreme exothermic 90 g. H 0 (5 moles) reaction. Yellowsolution. Cooled in ice box then let stand at room temperature. (4l.l%solids) 3 62 g. THP (0.5 mole) Mixed together at room tempera- 30 g.Urea (0.5 mole) ture and let stand for 4 hours 90 g. H 0 (5 moles) atroom temperature.

(50.5% solids) 4 62 g. THP (0.5 mole) Mixed together and heated at l5 g.Urea (0.25 mole) 80C for minutes. Cooled at 9 g. Formalin (0.l mole) inice box then let at 90 g. H 0 (5 moles) room temperature. (45.5% solids)5 62 g. THP (0.5 mole) Mixed together and left to H0 g. H O (6.l moles)stand at room temperature for 8l g. Dimethylamine.HCl minutes. Cooled inice box (I mole) then let stand at room temperature. (42.5% solids) 6 62g. THP (0.5 mole) Mixed together and left to 90 g. H 0 (5 moles) standat room temperature for 20.25 g. Dimethylamine.HCl 4 hours. (42.3%solids) (0.25 mole) 7 62 g. THP (0.5 mole) Mixed together and exothermic350 g. lsopropyl alcohol reaction produced a small 53 g. N-mcthylanilineamount of solid. Removed (0.5 mole) precipitate and stored solution atroom temperature until used. (24% solids) TABLE ll COPOLYMER SOLUTlONPHOSPHlNE ADDUCTS S USlNG SOLUBLE METHYLOL- OF TABLE l AND AN AMlNETABLE III PRODUCTION OF FLAME RESISTANT THERMOSETTI NG POLYMERS THROUGHUSE OF METHYLOLPHOSPHINE OR AMlDE ADDUCTS AND AMINES AND AMlDESDesignation Copolymer Description of Thermosetting Polymer of CopolymerSolut on Used Resulting from Heating the o olymer Solution Compositionof Copolymer Solution f( lIgnltI0lrl1) itsutioril lgrgrrrl labout l20 lfor mm a e out mutes A 97 g. of adduct No. l mixed with 15 g. of ureaand 29.2 g. H 0 (40 7. soln.) 5 Contains: 0.25 mole THP, 0.25 molecyunumidc 25 l (mm A Clear. hard, yellow colored polymer B 95 g. ofadduct No. 2 mixed i h Insoluble m H 0 and ethanol. Flame 32.4 g.trimethylol melamine and 83 g g a ki C(lmalns nitrogen H 0 (40% soln.) PP Contains: 0.25 mole THP. (H25 mole A cyanamide, 0 l25 mole C H 0. 50 Bg l l O a ii d C i-l O l liifrie a rili gl tfw and 0.15 mole TMM. I

C 9l g. of adduct No. 3 mixed with 87.0 g. imz gasf nnmgcnN,N'-dimethylol cthyleneurea (5071 soln.). mm W V7 p A H g p W and 44 g.H 0 (4071 -l C ClEarIwhite. hard polymer insoluble Contains: 0.25 moleTHP. 0.25 mole urea i H 0 a d C H OH, Flame a d glow and P S resistant.Contains nitrogen and D 88 g. of adduct No. 4 mixed with 2l.0 g. 5phosphorus.

"a a 'd' 507 c l .and 17.3 .H.O We A (mi "23 t; I *0 n l g l D Clear.hard. slightly yellow polymer Contains 025 mole THP (H25 mole ureamsllublc. m H1O Flame and (W62 mom CHLO and 0-25 molcglkpw rkesistant.Contains nitrogen and eyanamide. v v 7 E l2o g. of adduct No. 5 mixedwith l) g. of E Hard, tan colored.opaoue polyriier thiourea. 40 g. ofFormalm. and 23.8 g. insoluble in H 0 and C-,H OH. Flame and H 0 (407,.m) I glow resistant. Contains nitrogen and Contains: 0.25 mole THP.0.2i5in6ole thiourea. phosphorus.

" dinieth laminc. 0.05 molc TMM. lfllfi ljff V V y N G 232 g. of adduct0. 7 mixed with l l g. of G Clear, hard. yellow polymer insolubletrimethylol melamine.

Contains: 0.25 mole THP. 0.25 mole methylaniline. 0.05 mole TMM.

in H 0 and C H OH. Flame and glow resistant. Contains nitrogen andphosphorus.

TABLE IV PRODUCTION OF FLAME RESISTANT FIBROUS MATERIALS THROUGH USE OFMETHYLOLPHOSPHINE ADDUCTS AND AMINES AND AMIDES Approx. Flame CopolymcrAdd-n Resistance Solution Used Cure after M r h (D i ation ConditionsWashing Tcst from Table II) Structure Treated Min. "C Hand StrengthColor L A Cotton twill fabric 3 I60 3 Good Good White 20 A Cotton knitfabric 2 150 2 do. do. do. 60 A Cardboard 3 I l0 l4 do. Tan 180 APE/cotton blend fabric 3 I60 3 Good do. White IO B Cotton twill fabric 3I50 l6 Crisp do. do. 120 B Nonwoven cellulosic 6 I40 Good do. do. 90 Q.PI 1m Z 199a- 29,, km 191. .QQ-A l D Cotton twill fabric 3 160 3 Gooddo. do. 45 E Cotton double knit fabric 4 150 16 do. do. Slightly 120yellow F Cotton twill fabric 3 150 19 Crisp do. White 135 G Nonwoven 201 l0 Good do. do. "'75 We claim: 20 4. The process of claim 1 whereinthe step (b) nitrog- 1. A process for producing flame resistant organicfibrous materials, said process comprising:

a. reacting tris(hydroxymethyl) phosphine with a monomeric nitrogenouscompound containing a trivalent nitrogen atom substituted with at leastone hydrogen or methylol radical, so as to obtain a so]- ublemethylolphosphine adduct containing unre-,

acted methylol phosphorus radicals;

b. forming a solution of said soluble adduct and at least onenitrogenous compound containing a trivalent nitrogen atom substitutedwith at least two hy-' drogen or methylol radicals;

c. impregnating an organic fibrous material with said enous compound isan amide selected from the group consisting of thiourea, ethyleneurea,propyleneurea, dicyanamide, hydroxyethylcarbamate, octadecamide andacrylamide. "si'fiebr'oce's of claim 1 wherein the nitrogenous compoundof step (b) is an amine selected from the group consisting ofethylamine, methylamine, ethylene diamine, aniline and cetylamine.

6. The process of claim 1 wherein the step (a) nitrogenous compound isselected from the group consisting of methylamine, dimethylamine,ethylamine, diethyl- 'amine, phenylamine, diphenylamine,phenylmethylamine, methylcetylamine, dimethylamine-HCI and N-methylaniline, and the step (b) nitrogenous compound is selected fromthe group consisting of ethylamine, methylamine, ethylene diamine,aniline, amino acids and cetylamine.

7. The process of claim 1 wherein the impregnated material, aftercopolymerization and insolubilization has occurred, is exposed to anoxidant.

1. A PROCESS FOR PRODUCING FLAME RESISTANT ORGANIC FIBROUS MATERIALS,SAID PROCESS COMPRISING: A. REACTING TRIS(HYDROXYMETHYL) PHOSPHINE WITHA MONOMERIC NITROGENOUS COMPOUND CONTAINING A TRIVALENT NITROGEN ATOMSUBSTITUTED WITH AT LEAST ONE HYDROGEN OR METHYLOL RADICAL, SO AS TOOBTAIN A SOLUBLE METHYLOLPHOSPHINE ADDUCT CONTAINING UNREACTED METHYLOLPHOSPHORUS RADICALS; B. FORMING A SOLUTION OF SAID SOLUBLE ADDUCT AND ATLEAT ONE NITROGENOUS COMPOUND CONTAINING A TRIVALENT NITROGEN ATOMSUBSTITUTED WITH AT LEAST TWO HYDROGEN OR METHYLOL RADICALS; C.IMPREGNATING AN ORGANIC FIBROUS MATERIAL WITH SAID SOLUTION; AND D.HEATING THE IMPREGNATED MATERIAL AT FROM ABOUT 90*C. TO ABOUT 170*C.UNTIL COPOLYMERIZATION AND INSQLUBILIZATION OF THE ADDUCT ANDNITROGENOUS COMPOUND OCCURS.
 2. The process of claim 1 wherein the step(a) nitrogenous compound is an amide selected from the group consistingof formamide, thiourea, acrylamide, octadecylamide, glycine,sulfonamides and phosphoramides.
 3. The process of claim 1 wherein thestep (a) nitrogenous compound is an amine selected from the groupconsisting of methylamine, dimethylamine, ethylamine, diethylamine,phenylamine, diphenylamine, phenylmethylamine, methylcetylamine,dimethylamine-HCl and N-methylaniline.
 4. The process of claim 1 whereinthe step (b) nitrogenous compound is an amide selected from the groupconsisting of thiourea, ethyleneurea, propyleneurea, dicyanamide,hydroxyethylcarbamate, octadecamide and acrylamide.
 5. The process ofclaim 1 wherein the nitrogenous compound of step (b) is an amineselected from the group consisting of ethylamine, methylamine, ethylenediamine, aniline and cetylamine.
 6. The process of claim 1 wherein thestep (a) nitrogenous compound is selected from the group consisting ofmethylamine, dimethylamine, ethylamine, diethylamine, phenylamine,diphenylamine, phenylmethylamine, methylcetylamine, dimethylamine-HCland N-methylaniline, and the step (b) nitrogenous compound is selectedfrom the group consisting of ethylamine, methylamine, ethylene diamine,aniline, amino acids and cetylamine.
 7. The process of claim 1 whereinthe impregnated material, after copolymerization and insolubilizationhas occurred, is exposed to an oxidant.
 8. The process of claim 7wherein the oxidant is selected from the group consisting of a peroxide,perborate or peracid.
 9. The flame and glow resistant textile producedby the process of claim
 1. 10. The process of claim 1 wherein thetextile structure contains about 50 percent or more cellulosic fiber.